Allergy season is upon us once again, and with a growing number of allergy sufferers, many are wondering what is causing the uptick in allergies. In the US, peanut allergies in children rose from 0.4% to 1.4% between 1997 and 2008, and hospital admissions due to severe food allergies tripled in the UK between 1998 and 2018. Additionally, allergies can trigger asthma, which is continuing to rise globally. There has also been a rise in unusual allergies, such as alpha-gal syndrome, where people bitten by lone star ticks have strong reactions to red meat.
Medical anthropologist Theresa MacPhail attempts to explain what allergies actually are in her book, Allergic: How Our Immune System Reacts to a Changing World. One theory is that allergic reactions evolved as a way for the body to expel carcinogens and toxins, from insect stings to snake bites. However, the world has changed and our overactive immune systems have started to seem out of step with the threats we face. Growing seasons for crops are getting longer, exposing people to pollen earlier each spring. Changing diets and lifestyles are putting our microbiomes out of whack, perhaps making children more likely to become sensitized to food allergens. Stress might also influence our susceptibility to allergies.
Doctors do not completely agree on what an allergy is or how best to diagnose it, making it challenging to pinpoint the exact cause of the rise in allergies. For MacPhail, this question hits close to home. Her father died from anaphylactic shock after being stung by a solitary bee when she was just a child. While it is difficult to determine the specific cause of the increase in allergies, it is clear that something is out of balance. Hopefully, continued research can shed light on the allergy epidemic and lead to better treatments and perhaps even prevention methods in the future.